Russia's special prosecutor Robert Muller, who is investigating the possible intervention of the Russian Federation in the presidential campaign in the US in 2016, asked the country's president Donald Trump to send letters and documents from 2015.

The request for information concerns not only the president, but also nine of his closest advisers, including ex-head of Trump's campaign headquarters, Paul Manafort and former chief campaign strategist Stephen Bannon, reports on Monday, March 5, NBC.

Investigators want to study all electronic and paper letters, as well as documents, data on phone calls, hand-written records and other papers dated from November 1, 2015.

By that time, Trump had already been campaigning for 4.5 months,.

US intelligence officials suspect that the Kremlin intervened in the election campaign in the United States to help Donald Trump win elections. The special prosecutor, Robert Muller, appointed in May 2017, as well as several committees of the Congress, are investigating whether the members of Trump's election headquarters had conspired with the representatives of the Kremlin.

Source: DW.